#define   _CRT_SECURE_NO_WARNINGS 1
int missingNumber(int* nums, int numsSize)
{
    int N = numsSize;
    int x = 0;
    for (int i = 0; i < N; i++)
    {
        x ^= nums[i];
    }
    for (int j = 0; j <= N; j++)
    {
        x ^= j;
    }
    return x;
}